The priest of a Northern Virginia church has admitted to sexual contact with a minor at a different church and has resigned from his post, according to the Arlington Diocese.

In a letter released by the diocese Saturday, Bishop Michael F. Burbidge disclosed that the Rev. Christopher Mould was no longer be pastor of St. Andrew the Apostle Church in Clifton.

Mould admitted Tuesday that he “had sexual contact with a minor on one occasion” while parochial vicar at St. Thomas à Becket Church in Reston from 1992 to 1995, according to the bishop’s letter, which was posted on the diocese’s website.

After hearing Mould’s admission, Burbidge said, he reported it to Fairfax County police. Burbidge’s letter said Mould “holds no ecclesiastical office” after resigning.

Fairfax County police said Sunday that there is an active investigation into the case and that anyone with information should call detectives at 703-246-7800.

Mould did not immediately respond to a message left on his cellphone or a text.

In the letter, the bishop said the diocese is “fully committed to a zero-tolerance policy related to sexual abuse of minors.” Any such abuse, the letter said, “is a grave sin and a profound betrayal of trust.”

He expressed “heartfelt regret” to the individual who was harmed by Mould’s actions.

In the letter, Burbidge emphasized that before the recent “admission of guilt,” the Arlington Diocese had never received a complaint of sexual abuse or misconduct against Mould.

The letter said Mould has “expressed deep contrition” and accepts that the consequences will be “serious and severe.”

According to the letter, the bishop, acting in accordance with church policy, arranged for Mould to leave the rectory of St. Andrew the day of the admission. He was to reside at a place where he would not have contact with “any minor near a church or school property.”

The bishop wrote that he understood the information about Mould was “difficult” for parishioners to receive.

He said the actions taken were made necessary by “justice and a commitment to the protection of children and young people.” He also said he was sad about the effect they would have on the St. Andrew community.

Burbidge said he would provide in a timely manner for pastoral leadership of the Clifton parish.

Paul Schwartzman contributed to this report.